Common battery telephone equipment



Feb. 23, 1932. c, MacGREGOR COMMON BATTERY TELEPHONE EQUIPMENT'vvvvvvvvvvl NVENTQ Charl Patented Feb. 23, 1932 TENT 9F rice 1 CHARLESM. MACGREGUR, OF CHICAGO, ILLINOIS COMMON BATTERY TELEPHONE'EQUIPMENT'Application filed February 20, 1930. Serial No. 429,878.

material changes in the switchboard or exchange, thereby materiallyreducing the number of intricate parts both mechanical and electricalnow employed in the magneto type, and whereby the switchboard orexchange may be operated with greater economy than with switchboards ofmany more parts, relays, resistance coils, movable contacts, impedancecoils, etc., which latter necessitate intricate wiring in the circuits,sub jecting the same to considerable trouble in maintenance and expense.

A further object is to provide an improved equipment of this characterwhereby the subscriber is enabled to hold the operators attention to hissignal, whereas with the regular or ordinary magneto or old type ofswitchboard the subscribers signal was liable to be neglected, as theoperator, in the course of her work could, it too many drop signals fellto please her, or to cause her extra work, place the drops back tonormal by hand without plugging in the subscribers line jack.

It is another object of the present invention to provide improved meansfor preventing the return of the drop signal to normal until the plug isinserted into the line jack to establish the-desired connection, andimproved means for holding-the armature arm (if such a construction isemployed) of the drop signal up until the jack of the drop signal isplugged into, thus maintaining the I subscribers signal active until therequired attention.

A further object is to provide an improved equipment of this characterby means of the use of which the small towns or'a-reas will be furnishedwith thesame high-grade service that the larger manual switchboards giveat the present time and at a much lower cost.

To the attainment of these ends and the accomplishment of other new anduseful obhe is given tion of a telephone system,

jects as will appear, the invention consists in the features of noveltyin substantially the construction, combination and arrangement of theseveral partshereinafter more fully described and claimed and asillustrated in the accompanying drawing in which f v The figure IS adiagram illustrating a porsuch as one subscribers station, having acommon battery switchboard equipment constructed in accordance with theprinciples of this invention, incorporated therein.

Referring more particularly to the drawing thereference character Arepresents a subscribers station, B astorage battery for the system, C acharge rectifier for the battery B, D the operators visual signal hereshown as the usual magneto drop signal, E a drop coil, J one oftheoperators switchboardacks, F the jack sleeve, R a double coil relayincluded in the circuit between the battery B and the drop coil E, P ajack plug,

L a supervisory switchboard lamp, PL a line pilot lamp, PR a pilotrelay, and N an audible night alarm.

It should'be noted that the relay R is normally de-energized when thesubscribers're- I ceiver at the station A is upon the hook and when. thesubscribers line 10 11 is open.

When the subscriber removes his receiver from the telephone hook atstation A an electrical circuit is closed at the switchboard, from thebattery B, conductor 12, bus bar 13, conductor 14-, through the coil 15of relay R, conductor 16 to the line 10, thencethrough the closed switchat the station A, line 11, conductor 17, coil 18 of the relay R,conductor 19 to .bus bar 20, back to the batery through conductor 21. V

The relay R will then be energized, causing the contacts 22-28 to bemoved from their normal positions in engagement with the contacts 2'25into engagement respectively wit the contacts 26-27. A current will nowflow from the positive pole of the battery B'through the bus bar 13,conductor 28, coil or" the pilot relay PR, conductor 29 to a bus bar 80.Thence from the bus bar 80, through conductor 31 to the relay contact26, through the contact 23, to the contact 22, through the contact 27through the conductor 32, through the drop coil E, thence through thespring contact 33 on the jack J, through the ring 3% on the jack, thencethrough the conductor 35, through the conductor 11, through the coil 18of the relay B, through the conductor 19 to the bus bar 20, thencethrough the conductor 21 to the negative side of the battery B, therebycausing the drop signal D to be released on the visual signal.

This signal D remains active, that is, the drop coil E will remainenergized if a drop is used, until the switchboard plug P is insertedinto the jack J by the operator to answer the subscriber at the stationA.

The signal D will be permanently active whether the subscriber has hungup his receiver at the station A or not as the coil 18 of the relay R inthis circuit acts as a holding relay until the plug P is inserted intothe jack J. Upon the insertion of the plug into the jack J the contactbetween the spring and the ring 3 1 of the jack J will be opened bymoving the ring spring 23 i out of con tact with the spring contact 33,thereby breaking or opening the drop coil circuit or lamp circuit as thecase may be through the coil 18 of the relay R. When the subscriber nowplaces the receiver back upon the receiver hook, the circuit is openedthrough the relay R, die-energizing the relay with the result that thespring contacts 22 and 23 will then move back to normal positions, thatis out of engagement with the contacts 26-27 and into engagement withthe respective contacts 2a and 25.

The insertion of the plug P into the jack J the natural occurrence andregular practice in all manual telephone switchboards to establish aconnection to another subscribers line by the use of another switchboardplug wh ch is bridged on the plug P through the standard switch keys andcords. This pair of standard cords and plugs therefore completes theconnection between the subscriber at the station A and anothersubscriber who has the same kind of equipment attachment as that used tocomplete the telephone circuit at the subscribers station A.

When the subscriber at the station A is using the telephone inconnection with any other subscriber the plugs are inserted in the jacksas above indicated.

ll'hen the conversation is finished, both of the subscribers returntheir receivers to the respective hooks and thereby electrically openthe line circuits by opening the switches atthe respective stations.

In every instance, as with the plug P inserted in the jack J when theline circuit is open, a supervisory lamp L is lighted for the purpose ofsignaling the operator that the conversation is finished, and theoperation of the above supervisory lamp is as follows.

When the subscriber at the station A has removed his receiver from thehook and closed the circuit of the line and thus energized the relay Rin the manner already described, the plug P is inserted in the jack Jand no circuit will occur through the supervisory lamp L, because therelay R- will be energized and cause the contacts 22 and 23 torespectively engage the contacts 27-26, thereby opening the line to thsupervsory lamp L. hen, however, the receiver has been placed upon thehook by the subscriber at either station and the circuitof relay R isopened and the relay then lo-energized, then current from the positivepole of the battery B will flow through the conductor 12, to the bus bar13, through conductor 39, through supervisory lamp L, sleeve 38 of jackplug, sleeve F of jack J, line 3?, contact 25, contact 23, contact 22,contact 2%, conductor 36, conductor 19, bus bar 20, conductor 21, tonegative side of battery B, thereby lighting the supervisory lamp L, andwhich lamp remains lighted until the operator releases or removes theplug P from the jack J.

It will therefore be manifest that it will be impossible for theoperator to return the drop signal I), or render this visual signalinactive, without inserting the plug in the jack, as the relay B, whenthe receiver is removed at either of the stations will prevent the same,because when the receiver is removed trom the hook at the station, acircuit will be established through both of the coils of the relay asabove described. But when the receiver is placed back upon the hook atthe station a circuit will nevertheless remain established through oneof the coils of the relay R, and this latter circuit will becontinuously established through coil 18, whether the receiver is or isnot upon the hook at the station. Such circuit being as follows: Frombattery B, conductor 12, bus bar 13, conductor 28, pilot relay PR,conductor 29, to bus bar 30, conductor 31, contact 26, contact 23,contact 22, contact 27, conductor 32, drop coil E, spring 33, jack ring34;, conductor 35, line 11, conductor 17, through coil 18 of relay R,conductor 19, to bus bar 20, conductor 21, to negative side of batteryB.

Furthermore, with this improvement the equipment may be attached to thepresent magneto type of telephone switchboard and at the same time willnot only convert the magneto system into a common battery system butwill dispense with a great amount or equipment and many parts that arenow used in the present type of common battery switchboard of standardmanufacture, and materially reduce the expense of maintenance.

It is also possible by the use of a common battery system designed for aL0 to 48 volt battery that there will be a greater ci'liciency over the20 to 2% volt battery commonly used,

when charged with the more recent valve type of charging rectifiers.

\Vhat is claimed as new is 1. In combination a jack and'plug and drop ofa telephone switchboard, a source of electrical energy, and a relaybridged across the subscribers line and one coil of said relay arrangedin series with the coil of said drop and operating to maintain said coilalways etlectve to maintain the drop against being rendered inactive,until the said plug is inserted in said jack.

2. In combination a jack and plug and drop of a telephone switchboard, asource of electrical energy, a multiple coil relay bridged across thesubscribers line, one of said coils being arranged in series with thecoil of said drop and operating to maintain said drop coil alwayseffective to maintain the drop against being rendered inactive, untilthe said plug is inserted in said jack, and a supervisory signal devicearranged in the plug circuit and controlled by said relay.

3. In combination a jack and plug and drop of a telephone switchboard, asource of electrical energy, bridged across the subscribers line, one ofsaid coils being arranged in series with the coil of said drop andoperating to maintain said drop coil effective to hold the drop againstbeing rendered inactive regardless of the position of the receiver withrespect to the hook until the plug is inserted in the jack, a supervsoryvisual signal in series with the jack plug, and means controlled by saidrelay for rendering said supervisory signal active when the subscribersreceiver is upon the receiver hook.

l. In combination a. jack, a plug and drop of a telephone switchboard, asource of electrical energy, a relay bridged across a subscribers line,a supervisory signal in the jack plug line, said signal being maintainedinactive at all times when the receiver is removed from the receiverhook, and means responsive to the action of the said relay when thereceiver is placed upon the receiver hook for rendering and maintainingsaid supervisory si nal active until the ack.

5. In combination, a ack, a plug and a drop of a telephone switchboard,a multi-coil relay bridged across a subscribers line, one of the saidplug is removed from coils ofsaid relay being arranged in series withthe drop signal coil whereby the signal will be maintained against beingrendered inactive when the subscribers receiver is removed from thereceiver hook, until the said plug is inserted into the ack, the lastsaid relay coil being rendered inactive by the insertion of the plug inthe jack.

6. In combination, a ack, a plug and a drop of a telephone switchboard,a multi-coil relay bridged across a subscribers line, one of the coilsof said relay being arranged in series a multiple coil relay with thedrop signal coil whereby the signal will be maintained against beingrendered inactive when the subscribers receiver is re moved from thereceiver hook, until the said plug is inserted into the jack, the lastsaid coil of therelay being rendered inactive by the insertion of theplug in the jack, a supervisory signal in the jack plug line, and meansresponsive to the action of said relay when the receiver is upon thereceiver hook for rendering said supervisory signal active when the plugis in the jack. 7

7. In combination a jack and plug of a telephone switchboard, asubscribers signal on said board, and a multiple coil relay bridgedacross the subscribers line, one of said coils being arranged in serieswith said signal and operating to maintain said signal against beingrendered inactive until the plug is inserted into the jack.

8. In combination a jack and plug and subscribers signal of a magnetotelephone switchboard, a common battery equipment for attachmentherewith, embodying a multi-coil relay bridged across the subscribersline, one of said coils being arranged in series with said signal andoperating to maintain said signal against being rendered inactive untilthe plug is inserted into the jack, a supervisory signal in the jackplug line, and means operating to render said supervisory signal alwaysactive when the plug is in the jack and when the subscribers receiver ison the receiver hook, until the plug is removed from the jack.

9. In combination, a jack and plug of a telephone switchboard, asubscribers signal on said board, a double coil relay bridged across thesubscribers line, one of the coils of the relay being arranged in serieswith the said signal for maintaining said signal active and againstbeing rendered inactive except by the insertion of the plug in the jack,a supervisory signal in the jack plug line, the other coil of said relayoperating to control said supervisory signal and cause the latter to berendered active only when the plug is in the jack and when thesubscribers receiver is on the receiver hook.

In testimony whereof I have signed my name to this specification on this17th day of February, A. D. 1930.

-CHARLES M. MACGREGOR.

